Complementary Controller for File Products and Method for Controlling Same
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-27
To control the head position in file products (magnetic disk files), a number of problems have to be solved in order to produce a product which has high yields and high enough robustness to avoid failing in the field if file tolerances change due to aging or changing environments. These problems are Repeatable Run Out (RRO), Non-Repeatable Run Out (NRRO), external vibration, variation in part tolerances, both electrical and mechanical and, to a limited extent, resonances. The present method of controlling a file actuator substantially solves these problems and consists of receiving a measured position error signal (PES) from a file and, by using either state feedback or a compensation network, a current is derived which is then fed back into the file voice coil motor (VCM) to stabilize the file actuator.